Room air conditioners are used widely throughout the world, typical types of which are window air conditioners and separate air conditioners. Window air conditioner generally consists of an indoor heat exchanger, an indoor centrifugal blower, a sound absorbing plate, a motor, a compressor, an outdoor heat exchanger and an outdoor axial fan. It is easily mounted and is very reliable and economic, however the high operating noise can make people difficult to sleep or work. A separate air conditioner has been developed to overcome the drawbacks of the window air conditioners, which consists of an indoor heat exchanger, an indoor motor, an indoor crossflow blower, pipes for connecting the indoor unit and the outdoor portion, an outdoor heat exchanger, an outdoor motor, a compressor, low and high pressure valves, and an outdoor axial fan. While this kind of separate air conditioner overcomes drawbacks of the window air conditioner, such as high noise, mounting is very complicated. In particular, the pipeline system and power supply line are difficult to fit and connect in tall buildings, and this results in high cost.